Electrode assembly



Oct. 30, 1945. w SCOTT ELECTRODE ASSEMBLY Fi led June 22, 1944 Inventor.Edwin W. Scott, b 79 6A4 y His 2t torney.

Patented Oct. 30, 1945 Edwin W. Scott,- scotia, N. L,- essi' noi te Gen-Electric Company, a corporationctNew York "Ap licants-mane 22, 1944,sesame. 5411537" (chast -27.5)

6 Claims.

My invention relates electrode assemblies more particularly to an.improved starting electrode assembly adapted for use with electricdischarge devices employinga pool-type cathode.,

Electric discharge devices employing a cathode of conducting liquid anda startingelectrode a portion of (relatively high. resistance material.immersed in' the. liquid have 4 been I widetee Pa t cu ar w 'e large c rnts" Qonsiderable 'Tef has been experienced. with. the starting.lectrodel assemblies y used in. devices or this character. In

lone. the starting electrode assembly ina; support and supply,conductor? in v the form of ametalstrap Whichis bent around the end ofthe starting electrode at'the end thereof remote from the cathode. Theends ofthe strap eitendlatereuy fi'oin the starting electrode and ar'wit weidedt'ogetherf to close the loop tightbolit the eie trede; 'Wiiilthis construction lials g'lvn re sonably good service, there has been ,etendend for the electrode to become loose in theft-lender siterip'romnged'service, particularly in; installations where. men eperati'ngt'emperatures, such as sco 'te 1000'" c. are encountered.

Even where the? hoider is formed of a: metal havre nico the differencein expansion" between rorxnbetweeu the holderand the" 'eiectrode. 1 Assoonas appreciableioosening occurs; tnestarting actioh oi the electrodebecomes erratic and re- Placement or the electrode assembly is required.In accordance witl'i'th'e' teachings er my invention, rprovideanilmproved electrode" structure, of

the type described above; in which the tendency of the electrode tobecome loose'in the holder is eliminated. v

It lS an object of my invention to provide a new and improved electrodeassembly.

It is another object of my invention to provide a new and improvedholder for the starting a electrode of an electric discharge device.

It is a still further object of my invention to provide an improvedstarting electrode assembly for electric discharge devices of themercury pool type which is characterized by long life and consistentoperating characteristics.

For a better understanding of my invention,

reference may be heats the ic11ewing'deseriptien taken in connectionwitntheeecompanying drawing, and its scope will be pointed out in theappended claims. In the drawing, Fig. 1 illustrats my invention appliedtdar'i electric discharge device of the mercury-p601 type; Fig. 2

is an enlarged: view in pers ective of my 1thproved electrode holder,and Fig. '3 is an enlarged. View, partially in section, showing thedetails of construction of" improved electrode assembly;

Referringnow to the drawing, I have shown my invention inbddid iii anelectric discharge deviceeomprising' a meter cylindrical envelope Iwithin. which'is supported anap ode 2 6i graphite or other}suitable'i'natrial. aiiddei generally cylindrical in fo'fm' and has thelower face thereof supported in opposed relation to a cathode'31 whichecmprisesa pool of conducting liquid such as mercury. The anode issupported in insulated relation with respe'et'tc the envelope f by meansof a seal construction including a glass sleeve 4 which is sealed toanupstandm flange 5 supported on the upper end of the en} velope I. Theupper end of" the sleeve 4 is closed by a metal eaptto which is securedan anode lead-in conductor T. It will be understood that the mode 2 iSsupported from the cover 6 by a connecting stud I.

' T'he lower enact the enveiepe I is emsed by a header 8 which may; beresistance welded to the wallsoftheenvlope l'. A starting electrdde 9"is. providedwith the Ievver end thereof iliir'nrsed' in the cathode forthe purpose of initiating. a cathode spot when it: isoesired' toinitiate conduction by the electficdischarge device; The tip. of theelectrode 9 may be any one of e number of" the high resistancecomposition which have been employed for this urpose and preferablycomprise a mixture of high resistance materials such as boron carbideand boron nitride.

j Th starting. eieetre'ae supported ininsulated re aticn with ri spectte tueenvelope lby a suitebiesear censtraction maladies; a metal eyeletchanges and modifications as fall' within the trated in more detail inFig. 2. As illustrated in Fig. 2, the starting electrode 9 includes acylindrical shank portion I which may be formed of graphite and astarting tip I6 which is formed of a high resistance material or amixture of such materials. Near the upper end of the shank is provided acircumferential recess to receive the holder H which, f as illustrated,is formedfrorn a fiat strip of-meta1 which is wrappedi..about the shankand has the ends spot welded together at 2,388,096 v x I 18, In order toimprove the mechanical strength of the connection between the holder andthe starting electrode and to prevent the formation" having a firstportion surrounding said electrode of small arcs between the holder andthe sl anl; of the starting electrode,rtparticularly.at high operatingtemperatures, I provide an additional connection between the startingelectrode and the arms of the holder.

"th'eiull current of the starting electrode; it may 'be of relativelysmall sizeso' that the insertion of 'the end of the Connector within theshank of the starting electrode does not becomefa source of trouble orrequire that alarger shank be employed;

WhileI have shown and described a particular embodiment of my invention,it will be obvious/to those skilled in the art that changes andmodificationsmay be made without departing from my invention in itsbroader aspects, and I, therefore, aim in the appended claims to coverall such spirit and scope of my invention. l

' What I claim as new and desire to secure by Letters Patent of theUnited States is:

1. An electrode assembly for an electric discharge device comprising anelon'gated'electrode having a, resistance which is relatively high withrespect tothe remainderof the circuit in which it is c'onnected,a firstconductor'for supporting and supplying current to said electrodeincluding a portion encircling and tightly gripping one end of saidelectrode and provided with a portion for supporting said electrode froma lead-in conductor of the device and a secondconductor having one endsecured in an opening formed in said electrode and the other end'securedto said first As illustrated in Fig. 2, this connection comprises asubstantially.TU-;shaped true di s chaig device offthetyp empmymg a.liquid cathode com rising a' starting electrode having a,

tivelyhigh with respect to the remainder of the supporting saidelectrode from a lead-in conductor of the device, and a rigid conductorof substantially U shape having one end secured in an ropening formed:in said one endoi the :electrode and the other .end securedito saidfirst-conductor.

3. An electrode assembly comprising an elongated electrode ofcarbonaceous material, a first conductor for supporting and supplyingcurrent 'to said electrode including a metallic conductor near one endthereof and a second portion extending laterally from. said electrode,and means for preventingarcing between said electrode and said conductorincluding a second conductor having one end connected to said secondportion of said first conductor and the other end secured to saidelectrode in good electrical contact therewith.

' 4. An electrodeassembly-comprising anelon gatedelectrode ofcarbonaceous 'material,"-a'first conductor for supporting and supplyingcurrent to said electrode including a metallic conductor having a' firstportion surrounding said electrode near on'e'end thereof and a'second-portionextending laterally from saidelectror le,- and means forpreventing arcing between said electrode and said conductor includ ng arigidcondu'ctor of sub' 'stantially' U shape having one: arm'connectedto said'second portion of saidifirst' conductorfand the otherarm secured-in 'an' opening formedin said one end of said electrode toform agood electrical'connection between said U- shapedco'nduc tor andsaid electrode; f

5. A starting electrode assembly for an electric discharge device of thetype" employing a liquid cathode comprising a. starting electrode'havinga substantially cylindrical shank portion andjatip portion adapted to beimmersed 'injthe "liquid of the cathode, a support and'current supplycanductor for said electrode including Tanietallic niembersurroun'dingthe shankjof fsaid electrode,

and a rigid conductor or substantially U"sha'pe having one end securedto said current supply conductor and the other end positioned injanaxially extending opening formed in saidshank and having good electricalcontact therewith.

6. AstaitihQ eIectr de assembly for: anfleotr'ic substantiallycylindrical shank portion? and a'tip 1 portion adapted to immersed inthefliifuid- 'oi the cathode, a first conductor for supportingandsupplying current to said electrode including'a mjeta'l' strap.surrounding the shank of said electrode', and ajrigid ccn'ductcr ofslibstalfitiiillj'y "U shape having one end scure'd'to' said firstconductor and the dtherffid, positioned ifi a'jlld threadlng lyengagillg the walls of anaxianyier- F e P ie ere hi1 ea he s.

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